methods for treatment of underground lagerstaetten

摘要

1,100,051. Secondary recovery of oil from subterranean, formations. MOBIL OIL CORPORATION. 11. March, 1965 [16, March, 1964; 19, June, 1964; 26, June, 1964], No. 10374/65. Heading E1F. Oil is extracted from a subterranean formation by passing into and flowing in the formation under pressure a liquid that is either positive non-simple or shear-hardening, or both.A positive non-simple liquid is one whose viscosity varies in the same direction as the permeability when it flows in various porous solids at the same nominal shear rate this property occurring over a limited range of shear rates, and a shear-hardening liquid is one which has a range of shear rates in which increasing shear rate increases its apparent viscosity. The liquids exemplified are solutions containing metal, ammonium, amine and alkanolamine soaps, nitrocellulose in butyl acetate, copper cetyl phenyl ether sulphonate, amine chlorides and amine hydrosulphonates. The liquid may be injected into the production well through an injection well. The soaps may be used to convert at least a portion of the flooding liquid to positive non-simple and/or shear hardening liquid or the liquid may be used as a slug in conjunction with a flooding fluid. Electrolytes may be incorporated in the positive non-simple and/or shear-hardening liquids to control the pH.